Regression | Coefficients | Pr > F | |||
Linear | 0.2051 | <0.0001 | |||
Quadratic | 0.2258 | <0.0001 | |||
Cross product | 0.0016 | 0.5608 | |||
Total model | 0.4324 | <0.0001 | |||
Parameters | Coefficients | Pr > |t| | |||
Constants | 1.5141 | <0.0001 | |||
P | 0.0522 | <0.0001 | |||
Ca | 0.0086 | 0.0007 | |||
Mg | 0.0060 | 0.0268 | |||
P × P | −0.0005 | <0.0001 | |||
P × Ca | −0.00001 | 0.4696 | |||
P × Mg | −0.00002 | 0.2568 | |||
Ca × Ca | −0.0001 | 0.0012 | |||
Ca × Mg | 0.00001 | 0.6300 | |||
Mg × Mg | −0.00007 | 0.0121 | |||
P × Ca × Mg | 4.63 × 10−8 | 0.8953 | |||
Critical values | |||||
Factor | Critical doses (kg/ha) | Optimal doses (kg/ha) | RDG (t/ha) | ||
P | 48.49 | 41 |
| ||
Ca | 40.23 | 37 | 3.06 | ||
Mg | 33.07 | 29 |
| ||